全文获取类型
收费全文 | 676篇 |
免费 | 30篇 |
国内免费 | 2篇 |
出版年
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 21篇 |
2015年 | 41篇 |
2014年 | 40篇 |
2013年 | 41篇 |
2012年 | 62篇 |
2011年 | 50篇 |
2010年 | 33篇 |
2009年 | 31篇 |
2008年 | 48篇 |
2007年 | 44篇 |
2006年 | 32篇 |
2005年 | 47篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 22篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 11篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有708条查询结果,搜索用时 31 毫秒
1.
The purpose of this review is to provide an overview of the effects of adenovirus and influenza virus infections on obesity in various experimental models. We reviewed studies that were conducted within the past 10 years and were related to virus infection and obesity prevalence. Here, we discuss a different causal relationship between adenovirus and influenza infections with obesity. Adenovirus infection can cause obesity, whereas obesity can be a risk factor for increasing influenza virus infection and increases the risk of morbidity and mortality. The prevalence of obesity due to adenovirus infections may be due to an increase in glucose uptake and reduction in lipolysis caused by an increase in corticosterone secretion. Adenovirus infections may lead to increases in appetite by decreasing norepinephrine and leptin levels and also cause immune dysfunction. The relationship between obesity and influenza virus infection could be summarized by the following features: decreases in memory T-cell functionality and interferon (IFN)-α, IFN-β, and IFN-γ mRNA expression, increases in viral titer and infiltration, and impaired dendritic cell function in obese individuals. Moreover, leptin resistance may play an important role in increasing influenza virus infections in obese individuals. In conclusion, prevention of adenovirus infections could be a good approach for reducing obesity prevalence, and prevention of obesity could reduce influenza virus infections from the point of view of viral infections and obesity. 相似文献
2.
3.
Isolation and characterization of an unprocessed extracellular myeloperoxidase in HL-60 cell cultures 总被引:2,自引:0,他引:2
Extracellular myeloperoxidase of human myeloid leukemia HL-60 cells was purified to homogeneity from its culture supernatant by ammonium sulfate fractionation, CM-Sepharose column chromatography, and monoclonal antibody-Sepharose affinity column chromatography. The yield of enzyme activity was 38% that of the ammonium sulfate fraction. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified preparation gave a single band of approximately 84 kDa. Analysis of protein blot with antibodies specific for the light and heavy chains of myeloperoxidase indicated that the enzyme contained a light and a heavy chain in a single polypeptide. The amino-terminal amino acid sequence of the enzyme began at amino acid residue 155 of the 745-amino acid sequence predicted from myeloperoxidase cDNA, indicating that the enzyme consisted of 591 amino acids. Sucrose density gradient centrifugation of the enzyme showed that the enzyme was a monomeric form. In pulse-chase experiments on HL-60 cells with [35S]methionine, pulse-labeled myeloperoxidase precursors were shown to be processed to a light chain and a heavy chain of cellular enzyme. During a 3-day chase period, newly formed processed monomeric enzyme was converted to a dimeric form. 相似文献
4.
The water fern Azolla pinnata R. Br. was fumigated for 1 week with either 25, 50 or 100 nl 1−1 SO2 . The symbiosis of Azolla with Anabaena azollae (spp.) was severely damaged by atmospheric SO2 even at concentrations as low as 25 nl 1−1 , with significant reductions in growth, reduction of C2 H2 , NH3 assimilation, protein synthesis, and heterocyst development. These disturbances appear to be mainly responsible for the extreme sensitivity of this fern to atmospheric SO2 . Changes in violaxanthin/antheraxanthin and epoxy-lutein/lutein ratios also indicate that free radical products are induced by atmospheric SO2 . These results suggest that the Azolla-Anabaena symbiotic system is a very responsive and reliable lower plant model to study the detailed effects of total sulphur deposition upon the balances between various important plant metabolic processes. 相似文献
5.
We studied 27 embryos of 5-12 weeks gestational age where pregnancy was interrupted due to paramedical reasons, in order to find the developmental stages at which matrix vesicles appear in cartilage, and whether they are involved in the mineralization process. Specimens of long bones, lumbar and thoracic vertebral column were prepared for light, transmission and scanning electron microscopic studies. In the cartilaginous models of long bones, matrix vesicles were found amongst maturing and hypertrophic chondrocytes already by the 6th week after fertilization. By that stage, bone rudiments consisted of only cartilage that was not yet mineralized. In the vertebral column matrix, vesicles were found in the vertebral bodies amongst maturing and hypertrophic chondrocytes at the beginning of the 8th week. At that stage, although hypertrophy of chondrocytes was observed, mineralization was still absent. No matrix vesicles were found in the perichondrium, investing mesenchyme and intervertebral discs. Mineralization of cartilage in long bone rudiments started in the form of hydroxyapatite crystals within or around the matrix vesicles at 7 weeks of age and in the vertebral column at 11 weeks. As mineralization progressed, more hydroxyapatite crystals were observed around the matrix vesicles, forming typical calcospherites . Mineralization then progressed in the form described in other animals. 相似文献
6.
7.
Young Jun Kang Young Shin Kim Hyangsuk Hur Hee Sun Kim Hyo Jeong Hong 《Biotechnology letters》1999,21(5):375-380
The complete (encoding 55 amino acids, aa) or partial (encoding aa 1–26) preS2 region gene of hepatitis B virus (HBV) was fused to the 3-end of glutathion-S-transferase (GST) gene and expressed under the control of the inducible tac promoter in Escherichia coli at 37 °C. The fusion protein with the complete preS2 region was moderately expressed (8%) while the protein with the N-terminal 26 aa was expressed at a higher level, yielding about 20% of the total cellular proteins. The GST-preS2 (aa 1–26) protein, which contains the immunodominant epitope, was produced form the soluble protein fraction of the recombinant bacteria and purified by affinity chromatography using glutathione-agarose column. The purified preS2 fusion protein showed the antigenicity of preS2, as assessed by indirect and competitive ELISAs. 相似文献
8.
9.
Jung-Woo Seo Younghoon Kim Jinyoung Hur Kang-Sik Park Young-Wuk Cho 《Neurochemical research》2013,38(8):1648-1660
To elucidate the molecular events involved in early ischemic neuronal death, we performed two-dimensional proteome profiling of primary cultures of rat cortical neurons following chemical ischemia induced by the administration of sodium azide under glucose-free conditions. Using a lactic dehydrogenase assay and Western blot analysis of dephosporylation of the voltage-gated potassium channel Kv2.1, we determined duration of chemical ischemia of 2 h to be the relevant time-point for early ischemic neuronal death. Sixty-one proteins were differentially expressed, and 26 different proteins were identified by MALDI-TOF with Mascot database searching. The proteome data indicated that chemical ischemia altered the expression of 20 proteins that are involved in stress response/chaperone, brain development, cytoskeletal/structural proteins, metabolic enzymes, and calcium ion homeostasis. Western blotting and immunocytochemical studies of the 6-most functionally significant proteins showed that, in the ischemia-treated group, the expression of glucose-related protein 78, heat shock protein 90 alpha, and α-enolase was significantly increased, while the expression of inositol triphosphate receptor 1 and ATP synthase beta subunit was decreased. In addition, the expression of dihydropyrimidinase-like 3 showed a truncated pattern in the ischemia group. The changes in the expression of these proteins might be significant indicators of early ischemic neuronal death. 相似文献
10.
Production of phytoestrogen <Emphasis Type="Italic">S</Emphasis>-equol from daidzein in mixed culture of two anaerobic bacteria 总被引:1,自引:0,他引:1
An anaerobic incubation mixture of two bacterial strains Eggerthella sp. Julong 732 and Lactobacillus sp. Niu-O16, which have been known to transform dihydrodaidzein to S-equol and daidzein to dihydrodaidzein respectively, produced S-equol from daidzein through dihydrodaidzein. The biotransformation kinetics of daidzein by the mixed cultures showed that
the production of S-equol from daidzein was significantly enhanced, as compared to the production of S-equol from dihydrodaidzein by Eggerthella sp. Julong 732 alone. The substrate daidzein in the mixed culture was almost completely converted to S-equol in 24 h of anaerobic incubation. The increased production of S-equol from daidzein by the mixed culture is likely related to the increased bacterial numbers of Eggerthella sp. Julong 732. In the mixture cultures, the growth of Eggerthella sp. Julong 732 was significantly increased while the growth of Lactobacillus sp. Niu-O16 was suppressed as compared to either the single culture of Eggerthella sp. Julong 732 or Lactobacillus sp. Niu-O16. This is the first report in which two metabolic pathways to produce S-equol from daidzein by a mixed culture of bacteria isolated from human and bovine intestinal environments were successfully
linked under anaerobic conditions. 相似文献